buckingham



(No Model.)

0. L. BUCKINGHAM.

ELECTRIC ARC LAMP. No. 320,843. Patented June 23, 1886.

v I wuwm/bo c UNITED STATES PATENT OFFICE.

CHARLES L. BUOKINGHAM, OF NEWV YORK, N. Y.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 320,843, dated June 23, 1885.

Application filed January 14. 1885. (No model.)

To all whom it may concern.-

Be it known that I, CHARLES -L. BUOKING HAM, of the city, county, and State of New York, a citizen of the United States of America, have made a new and useful Improvement in Electric-Arc Lamps, of which the following is a specification.

My invention consists in the arrangement of suitable mechanism with a clutch adapted to sepaiate the carbons of an electric lamp and to establish the arc; to next unclamp the carbon-holder, leaving said carbon-holder suspended by a train of wheels, and to then return to its normal position and remain in readiness to re-establish the arc to its normal length in case of over-feeding upon the release of the geartrain. To this end, preferably, an arc branch electro-magnet is employed to raise the clutch, while a shunt electro-magnet next operates to short-circuit the arc branch electro-magnet upon the establishing of a normal are, thereby permitting the clutch to return to its normal position, and a second shuntmagnet serves to release the wheel-train which supports the carbon-holder upon an abnormal increase of arcresistance.

p is an arc branch electro-magnet, having a hollow axial armature, q, through which passes a cylindrical carbon-carrier, R. The axial armature q is provided with a lifting-toe, which serves to lift a clamping-ring, s, of a wellknown form, thus lifting the carbon-holder upward until the opposite side of the tilted clamping-ring is raised against alimiting-stop, r. h is a portion of the lamp-frame, upon which is supported a train of wheels, I) b c d e f g. The carbon-holder is provided with a longitudinal groove having rack-teeth whose crowns or points are flush with the cylindrical surface of said holder. By thus arranging the rack-teeth of the carbon-holder its surface is rendered suitable for use with the ring-clutch. The pinion b gears into the rack of the carbonholder and is rigidly fixed upon the same arbor to a ratchet-wheel, b. The Wheel cis provided with a pawl, cl, which takes into the teeth. of wheel 1), thereby communicating the downward force of the upper carbon, 0, and the carbon-holder R to the gear-train. WVhen, however, the carbon-holder is raised upward by the clamping-ring, the ratchet-teeth of wheel I) slide backward under the free end of point (1 without rotating other portions of the gear train than pinion b and wheel b. \Vheel g is the last wheel of the train, and is preferably a rotating escapementfly adapted to regulate the motion of the train. Armature j of shunt electromagnetic is adapted to arrest the rotation of the fiy-wheel y when in its back position, but to release said train when attracted by the shunt electro-magnet. Z is an electro-magnet, also placed in the shunt branch, which attracts its axial armatu re at the moment a normal arc is established, or much before It attracts armature j. It will now be seen that if carbon points 0 c are together, a current, when first passed over the line, will cause the carbon-h older to be raised through the agency of arc branch electro-magnet p. Armature j will at the same time hold the feed-train locked. When a normal arc is established,electromagnet 1) is short-circuit-ed through contact in and armature it, enough current having then been diverted through the shunt branch to cause electro-magnet Z to attract its armature to the front position. When short-circuited, electromagnetp loses its magnetism, and clamp 8 drops to its lowest position, and the carbon-holder is again free to slide through its cylindrical opening; but when the carbon-holder is released by the lifting-clamp it is sustained by the feedingtrain which still remains locked by armature j, and is only released when the carbon points have so far burned apart as to cause an abnormal arc-resistance. The armature n of electromagnet Z should be so adjusted that it will be promptly retracted upon a decrease of arc-resistance but little below the normal, thus causing the arc current to flow through 1), and again lift clutch s to reestablish the arc to its normal length.

Instead of a gear-train and a shunt-branch electro-magnet to effect feeding, a shunt-branch electro-magnet may be employed to release any well-kn0wn clamping device commonly used to suspend the carbon-holder and to feed the same as the carbons are consumed without departing from my invention. All that is necessary of a clamping device is that it shall admit of the raising of the carbon to establish an arc, to then hold the carbon suspended, and to permit the downward feed of the carbon under the action of gravity upon the occurrence of an arc of abnormal resistance.

hat I claim, and desire to secure by Letters Patent, is-

1. In an electric lamp, thecombination of a lifting-clutch, an arc-branch eleetro-magnet for raising said clutch, ashunt-branch electromagnct for causing the clutch to release the carbon-holder and return to its normal po sition, and a feeding device controlled by a slnint-branch electromagnet, which permits the carbon-h0lder to feed under the action of gravity.

2. The combination of an arc-branch electromagnet, alifting-elutch which is first actuated by said arc-branch electro-magnet, a carbonholder provided with rack-teeth which is lifted bysaid clutch, a shunt-branch electromagnet to control the release of said clutch from the carbon-holder and its return to its original position, a train of wheels which is normally locked for holding the carbon-holder suspended when it is released from the 1iftingclutch, and a shunt-branch electro-maguct for releasing said train of wheels to permit the carbons to feed.

3. The combination of a carbon-holder, a lii'tingclutch, an arc-branch electro-magnet adapted to raise said clutch and a shunt-branch electro-magnet for controlling its release and return to its original position, a gear-train for carbon-holder having rack-teeth with which 5 said wheel gears, and which is suspended against the action of gravity by said train, a shunt-branch electro-inagnet, an cscapenncntwheel controlled by said electro-1nagnet for releasing said train, a lifting-clutch adapted to raise the carbon-holder, and an electro-magnet for controlling the release and return of said clutch to its original position.

5. The combination of a suspending and feeding train of wheels, ashunt-branch electromagnet for controlling said train, a carbonholdcr, a clutch adapted to raise and release said carbonholder and to return to its original posit-ion in readiness to reestablish the are in case of over feeding, an arc-branch electro-magnet to control said clutch, and a second shunt-branch electro-magnet adapted to short-circuit the are-branch magnet upon the forming of a normal length of arc.

CHARLES L. BUOKINGHAM.

\Vitnesses:

\VM. ARNOUX, S. S. XVAT'rEns. 

